Beer begins on a farm and ends up in a glass

Brewing is a simple process that can be made very complicated with the application of scientific techniques to perfectly control the process. Here the process of brewing has been divided into six major steps.

Farm-grown hops are used almost exclusively for making beer. These green, cone-shaped flowers come from tall, fast-growing vines. Dozens of different hop varieties are grown, and each contributes a unique flavor to beer. After harvest, the hops are dried, baled, and shipped to the brewery.

Barley, a grain similar to wheat, serves as the basis of most beers. Other grains, such as corn or rice, may also be used, mainly as "adjunct" ingredients. Before it can be used in brewing, barley must first be "malted." The "maltster" soaks the barley in water to awaken the tiny proto-plant inside each barleycorn, and allows it to sprout for a very short time. This activates enzymes that start to convert starches in the kernel into simple sugars, primarily maltose. This malted barley is then dried. Maltsters roast some malt to produce darker colors and flavors that vary from biscuitlike to burnt.

Brewers combine ingredients in many combinations to produce different types and flavors of beer. First the brewer combines the malt and other grains with hot water to produce a mash. This converts the complex starches of the grains into simple sugars that can be fermented by yeast. Mashing yields an amber, sugar-filled liquid called wort.

Next the brewer boils the wort for 60 to 90 minutes. Hops added at various times during the boil produce different characteristics such as bitterness, flavor, and aroma.

After boiling, the brewer cools the wort and transfers it to a fermenter. Here yeast is added. Brewers pick from scores of different brewing yeasts, each of which will produce a slightly different character in the finished beer. The yeast type dictates the exact time and temperature of fermentation, but most do best under one of two general programs. Lagers ferment at 50 to 55F for 10 to 14 days, and then cold-condition (or lager) for two to eight weeks at 35 to 40F. By contrast, ales usually ferment at 65 to 70F and are generally ready for consumption within two weeks.

These days many brewers add specialty ingredients to their beers. They may add specialty grains such as oats or rye during the mash. Other ingredients such as honey, spices, and fruit may be added during the boil or even during fermentation.